462	RWTH Publication No: 684329        2017        IGPM462.pdf
TITLE	Incompressible Fluid Problems on Embedded Surfaces: Modeling and Variational Formulations
AUTHORS	Thomas Jankuhn, Maxim A. Olshanskii, Arnold Reusken
ABSTRACT	Governing equations of motion for a viscous incompressible material surface are derived from the balance laws of continuum mechanics. The surface is treated as a time-dependent smooth orientable manifold of codimension one in an ambient Euclidian space. We use elementary tangential calculus to derive the governing equations in terms of exterior differential operators in Cartesian coordinates. The resulting equations can be seen as the Navier-Stokes equations posed on an evolving manifold. We consider a splitting of the surface Navier-Stokes system into coupled equations for the tangential and normal motions of the material surface. We then restrict ourselves to the case of a geometrically stationary manifold of codimension one embedded in Rn. For this case, we present new well-posedness results for the simplified surface uid model consisting of the surface Stokes equations. Finally, we propose and analyze several alternative variational formulations for these surface Stokes problem, including constrained and penalized formulations, which are convenient for Galerkin discretization methods.
KEYWORDS	surface PDEs, Navier-Stokes on surfaces
DOI	10.4171/IFB/405
PUBLICATION	Interfaces and Free Boundaries 2018, 20(3), pp. 353-377